Crucible for growing crystalline silicon ingot and extracting silicon raw material of crystalline silicon ingot and preparation method and application thereof

Abstract

The invention discloses a crucible for growing a solar grade crystalline silicon ingot containing boron dopant and extracting the silicon raw material of the crystalline silicon ingot. The crucible comprises a crucible shell and a boron nitride liner covered on the internal surface of the crucible shell, wherein the thickness of the boron nitride liner is 0.001mm-4mm; the weight of boron nitride in the boron nitride liner is not more than 2% of the weight of silicon raw material added in the crucible; and the crucible shell is prepared from one or more materials of graphite, quartz and carbon / carbon composite through processing. The invention also discloses a preparation method and application of the crucible. The crucible of the invention solves the problem of the prior art that molten silicon leaks through the capillary tubes in the crucible and silicon adheres to the wall of the crucible so that the crucible or the silicon ingot is cracked or smashed, satisfies the demands of industrialization, large volume, low cost and long service life, has universal applicability and is particularly suitable for the production environment with high temperature and low pressure or the production environments with other special demands.

Description

technical field [0001] The invention belongs to the technical field of growth and purification of solar-grade crystalline silicon, and in particular relates to a crucible for growth of solar-grade boron-containing dopant crystalline silicon ingots and purification of silicon raw materials, as well as its preparation and application. Background technique [0002] Silicon material is the most commonly used material for crystalline silicon solar cells. Crystalline silicon ingots refer to monocrystalline silicon or polycrystalline silicon ingots produced by crystal pulling, directional solidification or casting methods that can be used for photovoltaic power generation. Usually, the purity of silicon in solar-grade crystalline silicon ingots is above 99.999%. In order to manufacture silicon ingots or purify silicon raw materials, silicon must first be turned into a molten state at high temperatures. The solubility of silicon is generally above 1412°C. Crucibles containing molt...

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Problems solved by technology

[0006] The invention provides a crucible for the growth of solar-grade boron-containing dopant crystalline silicon ingots and the purification of silicon raw materials, which solves the problem of silicon melt leaking through the capillary in the crucible and the adhesion of silicon on the crucible wall in the prior art. The resulting crucible or silicon ingot has cracks or even broken problems, which not only meet the requirements of industrialization, large volume, low cost, and long life, but also have universal applicability, especially for high temperature and low pressure (temperature above 1400 ° C, pressure at Below 1000Pa) or other specific requirements of the production environment

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